This invention relates to support structures using reinforced concrete.
It is known to use reinforced concrete to provide support for culverts and bridges and the like. In one class of such reinforced concrete supports, vertical reinforced concrete walls extend on either side of a waterway or other passageways. In this class of culverts or bridges, at least one horizontal reinforced concrete top member is supported by the vertical reinforced concrete walls to form a curved top surface that receives loads principally in compression and passes it to the sidewalls. In some constructions, dirt is applied over the top member.
In a prior art construction of this type, the reinforced concrete top member or members is integrally formed at least in part with the vertical side walls. For example, one such support structure is formed substantially as a plurality of inverted U-shaped elements that are laid side-by-side through the waterway to provide a path for a roadway over it, with dirt being applied on top to receive vehicles or the like.
This type of structure has several disadvantages, such as for example: (1) it is necessary to divert the waterway during construction in most instances to place the inverted U side walls properly; (2) it is difficult to transport the large U-shaped members to the location for construction; (3) a substantial weight of concrete is necessary to form the top surface; and (4) under some circumstances, the dirt on top of a culvert or bridge applies excessive extra load to the structure.